Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Gregory T Walker, MD

Urology Physician in Bloomington, IN · enumerated 2005 · practices at Indiana University Health Southern Indiana Physicians Urology.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1619975851

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Registry record

Entity type Individual (Type 1)

Name Gregory T Walker

Credential MD

Sex Male

Practice address 1520 S Liberty Dr, Bloomington, IN, 47403

Phone (812) 676-4300

Fax (812) 676-4301

Enumeration date Jul 12, 2005

Last updated in NPPES Jan 5, 2016

Taxonomy & licenses

208800000X Urology Physician Allopathic & Osteopathic Physicians · License 01033828A (IN) Primary

MD — Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

Other identifiers

Identifier	Type	State	Issuer
100167040	Medicaid	IN	—

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes — even if the provider moves or changes specialty.

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Frequently asked questions

Is this the official NPI registry?

No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.

What specialty is Gregory Walker?

Gregory Walker is registered in NPPES with the primary taxonomy of Urology Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2016-01-05.